Frances Tiafoe lost it on a chair umpire after being called for a time violation.

Tiafoe and Roman Safiullin were tied 5-5 in a third-set tiebreak at the Shanghai Masters when chair umpire Jimmy Pinoargote called Tiafoe for a time violation on his first serve.

Tiafoe was incredulous.

“No, no, no — I tossed the ball up!” he protested, repeating several times that he had tossed the ball up for a serve before being called for the violation.

The umpire did not engage Tiafoe other than to declare, “It’s second serve now.”

Tiafoe did not serve within the required 25 seconds following the previous point, but had done a serve toss while not hitting it.

The player and umpire disagreed on the semantics.

“Dude, that’s the rule!” Tiafoe continued. “The ball goes up, how am I not ready to serve?”

The umpire responded, “Second serve.”

Tiafoe proceeded to lose the next two points, and thus the second-round match.

After shaking hands with Safiullin, Tiafoe refused to shake hands with the chair umpire, and proceeded to berate him.

“F–k you man, f–k you! Seriously man, f–k you,” Tiafoe shouted, as the fans in the crowd laughed audibly.

“You f–ked me the f–king match. Three f–king hours, I’m f–king out here battling for my livelihood.”

Tiafoe, who recently made a run to the U.S. Open semifinals, is ranked 17th in the world while Safiullin is ranked No. 61.

By ATP rules, Tiafoe could face a fine of up to $60,000 for verbally abusing an official.

Tiafoe apologized for the outburst in a note in his Instagram Story.

“I really apologize for the way I acted tonight. That is not who I am and not how I ever want to treat people,” Tiafoe wrote.

“I let my frustration in the heat of the moment get the best of me and I’m extremely disappointed with how I handled the situation. That’s not acceptable behavior and I want to apologize to the umpire, the tournament, and the fans. I’ll be better for yall.”